Hillary Clinton, Tim Kaine make debut as running mates in Miami

Washington: Presumptive US Democratic presidential nominee Hillary Clinton and Virginia Senator Tim Kaine spoke for the first time as running mates at a rally in Miami, Florida on Saturday, two days before the party's convention kicks off in Philadelphia.

She formally introduced her low-key Spanish-fluent ally to the crowd at Florida International University, where the student body is more than half Hispanic.

"He is qualified to step into this job and lead on day one and he is a progressive who likes to get things down," said the former Secretary of State, with a grinning Kaine at her side.

At ease in the national limelight, Kaine showcased his fluency in Spanish, introduced himself and praising Clinton while attacking the Republican presidential nominee Donald Trump.

"Hillary Clinton is the direct opposite of Donald Trump," he said, claiming he and Clinton are "soulmates in this great fight" for progressive agenda.

Democratic presidential candidate Hillary Clinton is joined by Sen. Tim Kaine, D-Va., as she speaks at a rally at Florida International University Panther Arena in Miami, Saturday. AP

"From Atlantic City to his so-called university, he leaves a trail of broken promises and wrecked lives wherever he goes," Kaine said.

"We can't afford to let him do the same thing to our country," Kaine said of the New York billionaire, adding that Trump's foreign policy positions are even considered dangerous among Republicans.

Since Clinton announced her vice president pick via Tweet and text message to supporters on Friday, Trump has been ripping Kaine in a series of tweets, claiming the selection will unnerve supporters of Clinton's formal rival Bernie Sanders and therefore cause a floor fight at the upcoming Democratic convention.